by Mark Hyman
Dr. Yudkin went on to argue that the underlying cause of heart disease is sugar, not fat, caused by hormonal imbalances (from too much insulin). He said we should focus on getting rid of sugar, instead of the popular recommendation to substitute polyunsaturated omega-6 fats for saturated fats.12
The bottom line, according to Dr. Yudkin: Sugar is the bad guy here, not fat. He explained that the studies that linked fat and heart disease are the type of studies that cannot prove cause and effect and that actual scientific experiments proved that it was sugar that caused all the problems seen in heart disease (abnormal cholesterol, inflammation, thick blood, etc.).
This makes complete sense if you understand the biochemistry of cholesterol in the body. (See Chapter 5 to clear up the cholesterol confusion.) And even so, in 1961, based on Keys’ work, the American Heart Association took up the mantra of fat as the cause of heart disease. Time magazine featured Keys on the cover and dubbed him “Mr. Cholesterol.” They quoted him recommending we cut our dietary fat from 40 percent to 15 percent of calories and saturated fat from 17 percent to 4 percent, and his advice was cemented as fact. In the public consciousness, there was no turning back.
Despite the data that flooded in showing that cholesterol and dietary fat may not be the real drivers of heart disease—that sugar and refined carbs are the true drivers of heart disease,13 weight gain,14 and type 2 diabetes15—medical associations and the food industry pressed onward with the promotion of a low-fat diet for heart health.
Subsequently, in 1984, Keys published a follow-up study that reanalyzed the data and could not find any association between saturated fat and heart disease.16 But by that time, the diet-heart hypothesis was so entrenched, policies set, and the food industry mobilized to produce fat-free (high-carb) foods that there was no going back.
The most important finding came in 1999, when all the data from Dr. Keys’ Seven Countries study was analyzed again by the study’s lead Italian researcher, Alessandro Menotti. He discovered a remarkable finding when he looked at all categories of food, not just fats.17 He found that sugar had a higher correlation with heart disease than fat. Many others were on the trail of sugar and carbs as the driver of heart disease, including Dr. Pete Ahrens, one of the fathers of lipid research from Rockefeller University, and Dr. John Yudkin. In 1986, Dr. Yudkin said, “If only a small fraction of what we already know about the effects of sugar were revealed in relation to any other material used as a food additive, that material would be promptly banned.” In others words, sugar would not be approved as a safe additive by the Food and Drug Administration (FDA).
THE LOW-FAT PLANT-BASED DIET AND HEART DISEASE
Some doctors and scientists have made observations and performed research that have shown that low-fat diets may be very effective in many diseases, including Drs. Dean Ornish, Neal Barnard, Caldwell Esselstyn, and Colin Campbell. Dr. Dean Ornish, a friend and colleague, has been a proponent of the diet-heart hypothesis. His Preventive Medicine Research Institute has done some impressive research on low-fat plant-based diets and heart-disease reversal, the reversal of prostate cancer, and the lengthening of telomeres (the ends of our chromosomes, which typically shorten as we age). Clearly, eating a whole-foods plant-based diet works. He has been a tireless and passionate advocate of lifestyle change for the prevention and reversal of chronic disease and has profoundly and beneficially impacted many lives.
Dr. Ornish’s research around heart disease is controversial in the medical community. He studied a small sample, thirty-five men over five years. And the intervention was complex—smoking cessation, exercise, group support, stress reduction, and a 10 percent fat (very low-fat) vegetarian diet. Clearly there was an improvement in blood flow in the arteries and fewer heart attacks in the treatment group. But it is very difficult to determine which one of those interventions mattered the most. Was it the smoking cessation, stress reduction, exercise, group support—all of which have been proven to reduce the risk of heart attacks—or the low-fat vegetarian diet?
There are some indications that the low-fat diet may have had some adverse metabolic consequences. The low-fat group gained an average of seven pounds. And though their total cholesterol (244 to 162) and LDL (bad cholesterol) (164 to 86) decreased, their triglycerides went up (166 to 258) and their HDL (good cholesterol) went down (51 to 36)—bad signs of a higher-carb diet linked to insulin resistance and pre-diabetes.18
The real question is how would this compare in effectiveness to all the same interventions but with a high-quality, high-fat diet that included organic or grass-fed animal products—or even with a high-fat, high-quality plant-based diet? That study has never been done so we can’t know for sure. But Dr. Ornish took men who were eating the typical processed nutrient-poor standard American diet and put them on a whole-foods, low-fat, plant-based diet. Guaranteed that will improve anyone’s health. It doesn’t answer the question, though, of whether this is the best diet for weight loss and disease prevention. In fact in most studies of low-fat vs. low-carb diets for weight loss, the low-carb, high-fat diet prevails. In the A TO Z Weight Loss Study comparing the Ornish and Atkins diets (low-fat to high-fat) in 311 postmenopausal women for a year, the high-fat diet group achieved the quickest, most dramatic weight loss and had greater improvements in cardiovascular risk factors.19 More studies are needed for sure. We need to compare high-fat to low-fat vegan diets. And we need to compare vegan diets to what I call a Pegan diet (more on that in Chapter 10), which is mostly plant-based with moderate amounts of clean animal protein. But the evidence is overwhelmingly pointing to the fact that it is our processed high-sugar diet, not the fat, that is driving disease and obesity, and that the key is to switch to a whole-foods diet rich in plant foods but also higher in good fats. Even Dr. Ornish recommends restricting refined carbs and sugar and adding omega-3 fats as part of his program.
Clearly Dr. Ornish’s low-fat, whole-foods, low-sugar, plant-based diet worked when compared to a processed, high-sugar, and high-carb diet to reduce the burden of heart disease. What we don’t know is how this diet compares to a higher-fat, whole-foods, mostly plant-based diet containing nuts, seeds, olive and coconut oil, and some healthy grass-fed, antibiotic-, hormone- and pesticide-free animal protein. We need to study this. There are significant genetic differences in how people handle fats and carbs and there may be some who do better on lower-fat diets, and others who do better on higher-fat diets; but all do better on a whole-foods diet that is the opposite of the standard American diet, the worst diet on the planet, which we are now exporting to every country in the world.
HOW COULD THE EXPERTS BE WRONG?
It seems implausible that the main associations and organizations entrusted with creating public health recommendations and policies and led by the world’s experts could have gotten it so wrong. But they did, and that, too, plays a big part in how we got into this big, fat mess.
The American Diabetes Association (ADA), which for years recommended high-carb diets for type 2 diabetes, has moved toward advising people to limit their carb intake. But they still recommend that diabetics eat a low-fat diet,20 despite overwhelming evidence that carb restriction combined with higher-fat diets (up to 70 percent fat) are profoundly effective in treating and reversing type 2 diabetes.21 I have been at ADA meetings where the entire exhibit floor promotes diet, low-calorie, artificially sweetened low-fat goods in big booths sponsored by the food industry. Even though we know that artificial sweeteners actually cause type 2 diabetes22 and weight gain, slow metabolism, increase hunger,23 and alter gut flora or bacteria to promote obesity and type 2 diabetes,24 they are still recommended by the ADA, diabetes doctors, and registered dietitians. That’s right. Artificial sweeteners make you fat and diabetic!
The American Heart Association (AHA) partnered early with the National Institutes of Health (NIH) and funded most of the research on diet and heart disease. Their focus has been almost solely on the diet-heart hypothesis: the idea that fat, saturated fat, and dietary
cholesterol were the cause of heart disease because they raised blood cholesterol. But even though in a long-term follow-up of the famous Framingham study, LDL (bad cholesterol) was the least associated cholesterol indicator of heart attack risk, on its website, the AHA continues to promote the same outdated recommendations to cut back on fat:
Select fat-free, 1 percent fat, and low-fat dairy products.
Choose lean meats and poultry without skin and prepare them without added saturated and trans fat.
To lower cholesterol, reduce saturated fat to no more than 5 to 6 percent of total calories. For someone eating 2,000 calories a day, that’s about 13 grams of saturated fat.
Cut back on foods containing partially hydrogenated vegetable oils to reduce trans fat in your diet. (A good thing and something they got right!)
The AHA’s policies are shaped in part by the source of their funding. They get millions of dollars a year for giving their seal of approval to highly processed industrial foods like low-fat, high-fiber oat cereals, despite the fact that they often contain six different kinds of sugar.25
Despite recent multiple large and extensive reviews of the research that found no link between dietary fat, and especially saturated fat,26 and heart disease,27 these guidelines persist. Dr. Ronald Krauss, who chaired the guidelines committee of the AHA in the 1990s and is currently the director of atherosclerosis research at Children’s Hospital Oakland Research Institute, challenged their fervent belief that saturated fat was the cause of heart disease. Despite his protestations, they continued to lower the acceptable limits of saturated fat in the diet, and he resigned from the committee. Dr. Krauss has proven that saturated fat actually improves the type of cholesterol (from small, dense, dangerous to light, fluffy, benign cholesterol).28 He shows that it is, in fact, sugar and refined carbs that cause the most dangerous atherogenic, or heart disease–causing, type of cholesterol pattern.29
The Academy of Nutrition and Dietetics (AND), the organization for registered dietitians entrusted with providing nutrition advice to patients, is also on the low-fat bandwagon. I recently spoke at one of its annual meetings in Philadelphia and was shocked to see huge exhibits from the food industry promoting every type of high-sugar, low-fat processed food. A recent California chapter of AND had its lunch (which was mandatory for attendees) sponsored by McDonald’s. AND had thirty-eight food industry funders in 2011, including Coca-Cola, PepsiCo, Nestlé, National Cattlemen’s Beef Association, Mars, and many others. Corporate contributions are its largest source of income, generating nearly 40 percent of its total revenue.30
Makes you wonder: Why would they promote real food when they are funded by the food industry?
THE ROLE OF BIG GOVERNMENT
We can’t lay all the blame on the scientific community for our fat phobia and the worldwide obesity epidemic it spurred. It is only one leg of the tripod that landed us where we are today.
In the 1970s, when it became evident that rates of obesity and heart disease were increasing, certain well-meaning politicians held hearings on diet and heath to determine how to advise Americans.
Mark Hegsted, a professor of nutrition at Harvard, led the group of scientists that in 1977—under the auspices of Senator George McGovern’s Select Committee on Nutrition and Human Needs—issued the first Dietary Goals for the United States, the forerunner of the Dietary Guidelines for Americans. These guidelines, updated roughly every five years by the federal government, cemented the low-fat philosophy as the country’s official diet, despite many scientists’ testimony that the evidence for a low-fat diet was insufficient.31 A recent review of all the randomized controlled studies (not population studies) that existed before the actual guidelines were developed in 1980 found no evidence linking fat to heart disease.32
Hegsted was fiercely against saturated fat. His research had shown that manipulating the levels of fat in a person’s diet could drive the person’s total cholesterol levels up or down. Hegsted found in his experiments that saturated fats raised the levels of total and LDL (“bad” cholesterol), that polyunsaturated fats lowered total cholesterol, and that monounsaturated fats did not seem to have much of an effect. But it wasn’t proven that this was linked to heart disease, and at that time, we didn’t know that HDL, triglycerides, and the size of your LDL (bad cholesterol) mattered more than total cholesterol.
The Dietary Goals report called for Americans to increase their carbohydrate intake to 55 to 60 percent of their daily calories, reduce their fat intake from 40 to 30 percent of their calories, and limit saturated fat consumption to no more than 10 percent of calories. It also advised them to limit their dietary cholesterol to about 300 milligrams a day. To its credit, the government did recommend a reduction in sugar (but not refined carbs) by about 40 percent from what Americans were eating at the time to account for 15 percent of calories.
Americans were told that they could protect themselves against cardiovascular disease, diabetes, and other chronic ills by eating more fruits, vegetables, poultry, fish, and whole grains, and by cutting back on the saturated fat in meat, eggs, butter, and whole-fat milk. They were told to eat low-fat foods like skim milk and to replace the saturated fat in animal products with polyunsaturated and monounsaturated fats from vegetable oils.
In 1992, the US Department of Agriculture issued the now-infamous Food Guide Pyramid. Carbs were firmly situated at the bottom of the pyramid and Americans were told to eat six to eleven servings of bread, rice, cereal, and pasta a day. Fats were at the tippy top, and we were warned to eat them sparingly. Suddenly pasta was a health food and fat was demonized.
In 2010, MyPlate, our government’s new educational food icon, replaced the pyramid, and it was a slight improvement. But it still advises a low-fat diet and includes the recommendation that we eat more dairy, despite the fact that there is little scientific support for the health benefits that many people connect with dairy.33 Walter Willett, the Harvard School of Public Health chair of the Department of Nutrition, criticized MyPlate, saying, “Unfortunately, like the earlier U.S. Department of Agriculture pyramids, MyPlate mixes science with the influence of powerful agricultural interests, which is not the recipe for healthy eating.”34
The food industry has influenced governmental recommendations and dietary guidelines across the globe. In 2014 the British Medical Journal published a series of investigative reports that “uncovered evidence of the extraordinary extent to which key public health experts are involved with the sugar industry and related companies responsible for many of the products blamed for the obesity crisis through research grants, consultancy fees, and other forms of funding.”35
In 2003 the World Health Organization (WHO) recommended the reduction of sugar to less than 10 percent of calories, and the sugar lobby descended on the White House. Tommy Thompson, the secretary of Health and Human Services under George Bush, flew to Geneva to inform the WHO that if they published their report with limits on sugar, America’s funding of $406 million for the WHO would cease.36 It wasn’t until 12 years later, in 2015, that the WHO was brave enough to declare that “adults and children [should] reduce their daily intake of free sugars to less than 10 percent of their total energy intake. A further reduction to below 5 percent or roughly 25 grams (6 teaspoons) per day would provide additional health benefits.”37
In a conversation with a former secretary of agriculture, Ann Veneman, I asked why we couldn’t stop the use of $4 billion in food stamps to pay for sodas, or why we couldn’t change the US Dietary Guidelines to more closely match current nutrition science. Her response was sobering. “The food industry has a lock on Congress and the White House.” Unfortunately, the mission of the USDA is to set healthy nutrition policy and promote and market agricultural products to Americans, not necessarily provide the most accurate scientific recommendations. This is an inherent conflict. It is a veritable revolving door of jobs between the USDA and Big Ag and Big Food. Americans should insist on the establishment of a new Department of Food run through the
Department of Health and Human Services, which is paying for the consequences of harmful dietary recommendations through Medicare and Medicaid.
In 2015, the US Dietary Guidelines Advisory Committee quietly and with little fanfare ended the era of trumpeting low-fat diets for weight loss or health. After reviewing all the research, this group of scientists failed to find any reason to limit total fat or cholesterol in the diet. This was finally put into the official guidelines in late 2015.38 A discussion of these recommendations in the Journal of the American Medical Association by Dr. David Ludwig of Harvard and Dr. Dariush Mozaffarian underscored these findings.39 Dr. Mozaffarian said, “Low-fat diets have had unintended consequences, turning people away from healthy high-fat foods and toward foods rich in added sugars, starches, and refined grains. This has helped fuel the twin epidemics of obesity and diabetes in America. We really need to sing it from the rooftops that the low-fat diet concept is dead. There are no health benefits to it.”
After six decades of fearing fat, ding-dong, the witch is dead!
BIG FOOD JUMPS ON THE LOW-FAT BANDWAGON
The food industry happily complies with any fad or recommendation of the day. With the low-fat wave of advice, the industry got busy creating a massive shift in their products. They replaced saturated fats with “healthy vegetable oils” like margarine and shortening. The grand irony, of course, is that hydrogenated fat (aka trans fat) has turned out to be one of the only fats scientifically linked to heart disease.